His early music, composed primarily before 1930, is light in tone, and generally instrumental. These compositions were well-recieved by the public, and he won several awards, including the Carnegie Award in 1916.

However, in 1934, Howells' mentor, Sir Edward Elgar, passed away, and this death was followed closely by the death of Howells' young son, Michael. Following these tragedies, Howells did not compose for some time, and when he resumed his work, his music took on a more melancholy nature.

In his new style of composing, Howells frequently relied on religious themes, and often incorporated a choir. His most famous work, "Hymnus Paradisi", written for orchestra and chorus, comes from this time period closest to his son's death.